Digital clock

ABSTRACT

A digital clock comprising an indication section for indicating numerals which represents the time and a control section for forming required numerals. The indication section includes at least four electric lamp type numeral indicator each having seven-segmented electric bulbs which are selectively turned on or off to compose any required figure of 0 to 9. The control section includes switch means each electrically connected with corresponding one of the bulbs, and rotating drums one for each of said numeral indicators. The drums are rotated at respectively constant rate. The drums have control areas, such as grooves formed thereon which areas serve to actuate or deactuate the switch means according to the rotation of the drums to turn on or off the associated bulbs for providing digital indication of time.

finite States Patent Wakabayashi 1 Sept. 18, 1973 [541 DIGITAL CLOCK 1,220,109 3/1917 Heiny 340/338 [76] Inventor: Yasuo Wakabayashi, No. F-191 Kamakura, Primary Exammer-Rlchard B. Wilkinson 1362 293 AZa Hyakuyanato, Assistant Examiner-Edith C. S. Jackmon zushi city, Japan Attorney-Woodhams et al.

[22] Filed. Oct. 12, 1971 [57] ABSTRACT [21] App! 188'256 A digital clock comprising an indication section for indicating numerals which represents the time and a con- [30] F i A li ti P i it D t trol section for forming required numerals. The indica- Nov. 16, 1970 Japan 45/100183 includes at least four e ct ic lamp type nu- Apr. 28, 1971 Japan 46/027532 mdicmo' each having sevensegmemed electric bulbs which are selectively turned on or off to compose 52 us. C1. 58/50 R, 340/338 R any required figure 0 The Section [51] G04) 19/30 cludes switch means each electrically connected with [58] Field of Search 58/23 R, 50 R; "espcmding bulbs and mating drums 200/6139 166 R 166 A; 340/3094 3095, for each of said numeral indicators. The drums are ro- 336', 338 347, 373 tated at respectively constant rate. The drums have control areas, such as grooves formed thereon which [56] References Cited areas dserve tohactuate or dezctgate the switch means accor in to t e rotation o t e rums to turn on or of UNITED STATES PATENTS the assoc iated bulbs for providing digital indication of 3,410,082 11/1968 Taylor et a1 58/23 R ma 3,015,094 12/1961 Reynolds 340/338 Giersiepen 58/395 X 9 Claims, 11 Drawing Figures Patented Sept. 18, 1973 3 Sheets-Sheet INVENTOR. 1645410 #44/(45/1 VA 81 Patented, Sept. 18, 1973 FIG 10 3 Sheets-Sheet FIG.11

W124i .rzmumwmon m DIGITAL CLOCK The present invention relates to a digital clock with an indication section for giving indication of numerals by lighting lamps arranged in a predetermined pattern, which indication section is controlled by a control section of simple construction to indicate the time.

There have been widely marketed a variety of digital clocks which indicate the time in digital manner by moving or shifting accurately according to transition of time cylinders on which digits are printed or thin plates on which digits are respectively printed. However, when such prior art digital clocks are to be used to give digital indication of the time in the dark or in a dark place, it is difficult to give a distinct indication of the time and accordingly it is difficult to read out the indicated digits correctly unless the clock is located in the vicinity of the person who wants to read the time, because the conventional clocks of this kind do not include any means to illuminate the indication surface or they only contains neon lamps or miniature bulbs which cannot present sufficient illumination to the indication surfaces. Thedigital clocks of the electric lamp type widely used in the outdoor clocks are extremely complex in their construction and include a number of diodes, relays or the like so that they are expensive and bulky in size, which becomes an obstacle to their popularization.

The present invention is intended to overcome the above difficulties and it is therefore an object of the present invention to provide a digital clock comprising an insulating drum which is repeatedly rotated and halted accurately according to the transition of the time and a number of switches disposed in contact with the drum and actuated by the drum, said switches being used to turn on and off selected bulbs according to the time to provide electrically illuminated numerals for affording clean and bright digital indication of the time.

It is another object of the present invention to provide a digital clock wherein an auxiliary switch is connected to each of numeral indication circuits provided respectively for minute, -minute, hour and 10-hour indications, the auxiliary switches are mechanically operated to produce time difference between the instant when the auxiliary switches are operated and the instant when segment switches for controlling segments of bulbs are operated, and all segments are illuminated simultaneously to, indicate the time and simultaneously extinguished after the time indicated has elapsed.

It is another object of the present invention to provide a digital clock in which an indication section is releasably mounted on the control section and further rotatably mounted to the control section in its mounted position, so that the clock may be located at any desired position and the indication thereof is visible from any direction by merely rotating the indication section.

It is another object of the presentinvention to provide adigital clock in which a-relay which controls large current is driven by the operation of a switch in the control section and an electric lamp of large size such as a fluorescent lamp is turned on through the operation of the relay, so that it is possible to construct a large indication section and to make use of the clock as an outdoor clock.

It is a further object of the present invention to provide a digital clock which is simpler in its construction and lower in its manufacturing cost as compared with conventional clocks and which facilitates the manufacture of clocks of any desired size ranging from a small one to a big one.

The present invention will now be described in more detail with reference to the accompanying drawings which show preferred embodiments of the present invention, in which;

FIG. 1 is a perspective view of a digital clock embodying the present invention;

FIG. 2 is a perspective view ofa seven-segmented numeric indicator with seven lamps which forms an indication section;

FIG. 3 is a perspective view of a control bodying the present invention;

FIG. 4 is a perspective view of a control section further embodying the present invention;

FIG. 5 is an electric circuit diagram showing the wiring between the numeral indicator of the indication section and switches of the control section;

FIG. 6 is an electric circuit diagram showing the connection of auxiliary switches for time difference operation with the circuit shownin FIG. 4;

FIGS. 7, 8 and 9 are diagrammatical views showing the relationship between the switches and the drum in operational steps;

FIG. 10 is a longitudinal sectional view of an interlink mechanism between the indication section and the control section; and

FIG. 11 shows an electric circuit diagram for actuating a lamp, such as fluorescent lamp, energized by an external power supply.

In the drawings and the following descriptions, like portions of parts are denoted by like numerals or characters.

According to the present invention, there is provided a digital clock comprising an indication section for indicating numerals representing time provided with at least four electric lamp type numeral indicators each including a plurality of segmented electric bulbs adapted to be selectively turned on or off to compose any one of figures 0 to 9; and a control section including a plurality of switch means each electrically connected with the respective electric bulbs for forming the electric lamp type numeral indicator and drums provided for respective electric lamp type numeral insection emdicators; each drum having a plurality of control areas.

formed thereon for respective switch means and being rotated at a constant rate, whereby said switch means being actuated or deactuatedunder the control of said control areas with the rotation of the drums to turn on or off the associated bulbs for providing digital indication of the time.

Referring to FIG. 1, there is illustrated one embodiment of the present invention. Character A represents an indication section and character B represents a control section. The indication section A has, as described later, four electric lamp numeric indicators 1 incorporated therein 30 and the control section B has a radio receiver set and a switching arrangement 2 incorporated therein which is also described later.

The electric lamp indicator 1 is of seven-segmented structure in which seven segment indicators la, lb, 1c, 1d, le, if and lg, each constructed mainly of an electric bulb, are arranged in the shape of figure 8" as shown in FIG. 2. By lighting some of the segment indicators, for example'the segment indicators la, 1d, le, If and lg, the figure 3" is indicated. FIG. 5 shows an electric circuit diagram of the switches 2a, 2b, 2c, 2d, 2e, 2fand 2g in the switching arrangement 2 for operating respective segment indicators 1a through 1g of the electric lamp numeric indicator 1. In this circuit, each of the segment indicators 1a through lg is connected in series with the corresponding one of the switches 2a through 2g, such series connections being, in turn, connected in parallel with a power supply 5. When the figure 3, for example, is to be displayed in the electric lamp indicator 1, five switches in the circuit shown in FIG. 5, i.e. the switches 20, 2d, 2e, 2fand 2g are simultaneously closed to turn on the segment indicators la, 1d, 1e, If and 1g for indicating the desired figure 3." Thus, by selectively closing appropriate combination of the seven switches 20 through 2g, each of ten figures, i.e. the figures l, 2, 3, 4," 5, 6, 7, 8, 9 and can be indicated.

An apparatus for operating the switching arrangement 2 will now be described. As shown in FIG. 3, seven microswitches 2a through 2g are provided for each of the electric lamp numeral indicators 1. Namely, one set of seven microswitches are provided for a minute indication, another set of seven micro-switches are provided for a l0-minute indication and a further set of seven microswitches for an hour indication. However, only two microswitches are provided for a 10-hour indication because only the figure l is required to be turned on or turned off in the 10-hour indication and such a figure can be indicated by two segment indicator, either 1g and lfor 1b and 1c. For each of the electric lamp numeral indicators 1 is arranged a drum 3 which completes one revolution in a predetermined time period. The drum associated with the microswitches for the minute indication rotates at a rate of one revolution per minute, and the drum associated with the microswitches for the 10s minute-indication is stepped every complete revolution of the drum for the minute indication. The drum associated with the microswitches for the hour indication is advanced by one step every complete revolution of the drum for the 10- minute indication, while the drum associated with the microswitches for the lO-hour indication is advanced by one step every complete revolution of the drum for the hour indication. On the circumferential surface of each drum, there are provided a plurality of grooves or control areas 30 in such an arrangement to operate the microswitches and indicate 1 to 2", 2" to 3 and so on successively, every step of the drum. Although only the assembly for the minute-indication is shown in FIG. 3, other assemblies for the IO-minute indication, the hour indication and the lO-hour indication are also mounted on a common-shaft 4. The shaft 4 is coupled, through a suitable means, to an output shaft of a speed reduction device which, in turn, is rotated at a constant rate by a synchronous motor.

A modification of the foregoing embodiment is shown in FIG. 4 wherein metal strip switches are used in place of the micro-switches 2a through 2g of, the switch arrangement 2 described above. The metal strip switches comprises a plurality of movable strips 21a through 21g, each having its one end fixed to'an insulating board 22, and a fixed contact piece 21 for receiv-- ing free ends of the movable strips. Each of movable strips has a projecting bend at its intermediate portion. The movable strips 21a through 21g and thefixed contact piece 21 are so arranged with respect to the drum that when the projecting bends of the strips fall .into

grooves or control areas 31a formed in a drum 31, the free ends of the strips are brought into contact with the contact piece 21. The principle of the operation is essentially the same as the previous embodiment in which the micro-switches 2a through 2g are used.

If the electric lamp numeral indicators 1 and the switch arrangements 2 are connected as shown in FIG. 5 (in which a single indicator 1 and a single switching arrangement 2 are shown) and the switches 2a or 21a, 2d or 21d, 2e or 2le, 2for 2lfand 2g or 21g are closed by appropriate rotational position of the drum 3 or 3],

only the segments la, 1d, le, lfand 1g of the seven segments are connected to the power supply 5 to be turned on. Thus, the figure 3" is indicated. In a similar way, other three switching arrangements 2 are operated to control corresponding numeral indicators 1 to digitally indicate the time.

The switching arrangement comprising metal strips (FIG. 4) is more economical and made small-sized more than that using micro-switches as shown in FIG. 3. Although the combination of moving strips and the fixed contact piece 21 was shown in FIG. 4, the drum 31 may be made of conductive material and the land portions thereof may be coated with insulating material for the same purpose.

Another embodiment of the present invention will now be described in connection with FIGS. 6 to 9. The present embodiment is intended to simultaneously turn on the segments la through lg of the electric lamp numeral indicator 1 at the instant of the time transition.

In the previous embodiment, due to the mechanical tolerance of the grooves 3a or 310 arranged for the drum 3 or 31 for operating the switching arrangement 2, the tolerance of the configuration of the switches and positional error in mounting the assembly, all of the segments to be turned on are not exactly simultaneously lighted and they are lighted at different instants to compose a required figure. Furthermore, when the indicated figure is to be extinguished after 1 minute of the indication and the next figure is to be indicated, the segments composing the figure disappear at different instants and the segments for composing said next figure are not simultaneously lighted. The present embodiment overcomes such non-simultaneous turn-on and turn-off of the segments la through 13. For the purpose, there is provided an auxiliary switch 23 which is added to the circuit of FIG. 5 in series with the power supply 5, as shown in FIG. 6. The auxiliary switch 23 is juxtaposed with the segment switches and a separate track of the drum 3, 31 having grooves 31b (as shown in FIGS. 7 to 9) is additionally provided for the switch 23. The grooves 31b for the auxiliary switch 23 are fonned in somewhat different manner from those for the segment switches 20 through 2g or 210 through 21g. Stated illustratively, when the drum is rotated to initiate the turn-on of the segments, a movable contact 230 of the auxiliary switch 23 may be operated to close its fixed contact immediately after all of the segment switches required to form a desired figure have been closed by the grooves on the drum. When the indicated figure is to be extinguished, the auxiliary switch 23 is first opened as soon as the drum 3 or 31 has initiated its rotation to open the segment switches, and then the segment switches are opened. Thus, a time difference is provided between the instant when the auxiliary switch 23 is operated and the instant when the segment switches are operated.

One example of the operation with such a time difference feature will now be described.

Referring to FIG. 7, the movable contact piece 21a and the juxtaposed movable contact piece 23a of the auxiliary switch 23 are arranged to make contact with the fixed contact piece 21 when the projecting bends of the movable piece 21a and the movable contact piece 23a of the auxiliary switch 23 butt against the grooves or control areas 31a and 31b, respectively. FIG. 7 shows a movement during the rotation of the drum 3 in a direction indicated by an arrow when the movable contact piece 21a has begun to be operated by the recess 31a on the drum surface and brought into contact with the fixed contact piece 211 while the movable contact piece 23a of the auxiliary switch 23 has not yet brought into contact with the fixed contact piece 21 due to the difference of the shape of the recess 31b. FIG. 8 shows a position at which the drum 3 is stopped after effecting one-tenth of its revolution. In this position both the movable contact pieces 21a and 23a are brought into contact with the contact piece 21 and both the switches are closed. FIG. 9 illustrates the turn-off operation in which the auxiliary switch 23 has been opened as soon as the drum 31 has initiated its rotation from the rest position of FIG. 8 while the movable contact piece 2la is kept in contact with the fixed contact piece 21. Thus, a plurality of parallelconnected segment switches can be connected to a single basic unit, and several electric lamp numeral indicator boards can be controlled simultaneously by one basic unit. This feature is advantageous for those homes or offices where a number of clocks are used.

Interconnection between the indication section A and the control section B is described with reference to FIG. lltl, in which numeral 6 represents a casing of the indicator section A. Secured to a bottom plate of the casing by means of screws or the like is a fitting 61 having tubular portion 61a. Numeral 7 represents a casing of the control section B and a sleeve 71 is secured to a top plate of the casing 7 by a nut 72. The tubular portion Ma of the fitting 61 is rotatably fitted in the sleeve '71.

With this construction, since the indication section A is rotatably mounted on the control section B, the indication section A may be directed to any desired direction. By connecting long lead wires through the tubular portion 61a (which lead wires serve to connect the switching arrangement Z in the control section B with the electric lamp digit indicator 1), it is possible to locate the indication section A at a distant position from the control section B after removing the indication section A from the control section B. It is also possible to branch the lead wires to another indication section A and control two or more indication sections A through a single control section B.

Referring now to FIG.- 11 which illustrates another embodiment of the present invention wherein a lamp, such as a fluorescent lamp, adapted to be lighted by a large current and located outdoors is used to indicate the time. The segment indicators 1a through llg shown in the basic circuit of FIG. 5 are replaced by relays 8a through 8g in FIG. ill. Through the contacts of the relays 8a through 8g, fluorescent lamps 81a through 81g are connected to an A.C. power supply 9. The switching arrangement 2 is the same as in the previous embodiment; the drum 3 or 31 completes its revolution at the predetermined rate, and when selected ones of the switches 2a or 21a, 23 or 21g are closed, selected stages of the relays 8a, 8g corresponding to the closed switches are actuated. Thus the desired stages of the fluorescent lamps 81a, 81g connected to the actuated relays are connected to the power supply 9 to be lighted on. If the fluorescent lamps 81a, 81g are installed outdoors, the assembly of the present invention may be used as an electric lamp type clock.

What is claimed is:

l. A digital clock comprising an indication section and a control section, said indication section comprising at least four electric lamp numeral indicators arranged for displaying numbers indicating (1) minutesunits, (2) minutes-tens, (3) hours-units and (4) hourstens, the indicators (1), (2) and (3) each consisting of seven elongated electric bulbs substantially defining the sides of two adjoining rectangles having a common side so that by selectively turning on and turning off the bulbs any one of the numbers 0 to 9 can be displayed by each of said indicators (1), 2) and (3), the indicator (4) having bulbs for displaying at least the number said control section including a plurality of switch arrays, one for each indicator, each array including a separate switch for each bulb of its associated indicator, said switches being connected in circuit with a power source and said bulbs for turning on and turning off said bulbs, a plurality of rotatable drums, one for each switch array, each drum having a separate peripheral track for each switch of its associated array, said tracks having control areas for opening and closing said switches in response to rotation of said drums in selected sequence so that the lamps will be turned on and turned off to provide a digital display of the time.

2. A digital clock as claimed in claim 1, which further comprises an auxiliary switch means connected in series between said switches and said power supply, and an additional track on the drum for said indicator (1); said additional track of the drum having a plurality of control areas which are adapted to open said auxiliary switch means before said switches are opened and to close said auxiliary switch means after said switches are closed, whereby all of the bulbs required to be turned on or off are energized and deenergized simultaneously.

3. A digital clock as claimed in claim 2, in which said control areas are grooves in the tracks on the periphery of said drums, the grooves in said additional track being of greater width than the grooves in the other tracks so that said auxiliary switch means opens before and closes after said switches.

4. A digital clock as claimed in claim 1, which further comprises a plurality of relays having their contacts connected between the respective bulbs and said power supply and adapted for energizing said bulbs, said relays being electrically connected to the respective switch means.

5. A digital clock as claimed in claim ll, wherein said switches are microswitches connected in series between said power source and said bulbs.

6. A digital clock as claimed in claim 1, wherein said switches comprise a plurality of movable contact arms of conductive material which are electrically connected in series with the respective bulbs of the electric lamp type numeral indicators, and a fixed contact piece mounted in opposing relation to said movable contact arms.

7. A digital clock as claimed in claim 1, wherein said drums are made of conductive material and have nonconductive areas formed thereon, said switch means being composed of said drums and a plurality of movable contact arms of conductive material electrically connected to the respective bulbs of the electric lamp type numeral indicators.

8. A digital clock as claimed in claim 1, wherein said indication section is rotatably and removably mounted on the control section and is connected to said control section by lead wires.

9. A digital clock comprising an indication section for indicating numerals representing time provided with at least four segment type numeral indicators each including a plurality of segmented elongated electric illumination means adapted to be selectively turned on or off to compose any one of Figures 0 to 9; and a control section including a plurality of switch means each electrically connected with the respective segmented elongate electric illumination means for forming the segment type numeral indicator and at least three drums provided for respective segment type numeral indicators; each drum having a plurality of control areas formed thereon for respective switch means and being rotated at a constant rate, whereby said switch means being actuated or deactuated under the control of said control areas with the rotation of the drums to turn on or off the associated segmented elongate illumination means for providing digital indication of the time. 

1. A digital clock comprising an indication section and a control section, said indication section comprising at least four electric lamp numeral indicators arranged for displaying numbers indicating (1) minutes-units, (2) minutes-tens, (3) hours-units and (4) hours-tens, the indicators (1), (2) and (3) each consisting of seven elongated electric bulbs substantially defining the sides of two adjoining rectangles having a common side so that by selectively turning on and turning off the bulbs any one of the numbers 0 to 9 can be displayed by each of said indicators (1), (2) and (3), the indicator (4) having bulbs for displaying at least the number 1; said control section including a plurality of switch arrays, one for each indicator, each array including a separate switch for each bulb of its associated indicator, said switches being connected in circuit with a power source and said bulbs for turning on and turning off said bulbs, a plurality of rotatable drums, one for each switch array, each drum having a separate peripheral track for each switch of its associated array, said tracks having control areas for opening and closing said switches in response to rotation of said drums in selected sequence so that the lamps will be turned on and turned off to provide a digital display of the time.
 2. A digital clock as claimed in claim 1, which further comprises an auxiliary switch means connected in series between said switches and said power supply, and an additional track on the drum for said indicator (1); said additional track of the drum having a plurality of control areas which are adapted to open said auxiliary switch means before said switches are opened and to close said auxiliary switch means after said switches are closed, whereby all of the bulbs required to be turned on or off are energized and deenergized simultaneously.
 3. A digital clock as claimed in claim 2, in which said control areas are grooves in the tracks on the periphery of said drums, the grooves in said additional track being of greater width than the grooves in the other tracks so that said auxiliary switch means opens before and closes after said switches.
 4. A digital clock as claimed in claim 1, which further comprises a plurality of relays having their contacts connected between the respective bulbs and said power supply and adapted for energizing said bulbs, said relays being electrically connected to the respective switch means.
 5. A digital clock as claimed in claim 1, wherein said switches are microswitches connected in series between said power source and said bulbs.
 6. A digital clock as claimed in claim 1, wherein said switches comprise a plurality of movable contact arms of conductive material which are electrically connected in series with the respective bulbs of the electric lamp type numeral indicators, and a fixed contact piece mounted in opposing relation to said movable contact arms.
 7. A digital clock as claimed in claim 1, wherein said drums are made of conductive material and have nonconductive areas formed thereon, said switch means being composed of said drums and a plurality of movable contact arms of conductive material electrically connected to the respective bulbs of the electric lamp type numeral indicators.
 8. A digital clock as claimed in claim 1, wherein said indication section is rotatably and removably mounted on the control section and is connected to said control section by lead wires.
 9. A digital clock comprising an indication section for indicating numerals representing time provided with at least four segment type numeral indicators each including a plurality of segmented elongated electric illumiNation means adapted to be selectively turned on or off to compose any one of Figures 0 to 9; and a control section including a plurality of switch means each electrically connected with the respective segmented elongate electric illumination means for forming the segment type numeral indicator and at least three drums provided for respective segment type numeral indicators; each drum having a plurality of control areas formed thereon for respective switch means and being rotated at a constant rate, whereby said switch means being actuated or deactuated under the control of said control areas with the rotation of the drums to turn on or off the associated segmented elongate illumination means for providing digital indication of the time. 